1. Technical Field
The present invention relates to a semiconductor light emitting element using group-III nitride semiconductors and a light emitting device provided with a semiconductor light emitting element.
2. Related Art
Generally, a semiconductor light emitting element using group-III nitride semiconductors includes a light emitting layer composed of a group-III nitride semiconductor between an n-type group-III nitride semiconductor layer and a p-type group-III nitride semiconductor layer. The n-type group-III nitride semiconductor layer contains n-type impurities for generating electrons as carriers, and the p-type group-III nitride semiconductor layer contains p-type impurities for generating holes as carriers. In this type of semiconductor light emitting elements, it is known that the light emitting layer has a multiquantum well structure including plural well layers and barrier layers alternately stacked (refer to Japanese Patent Application Laid-Open Publication No. 2011-222812).
Even such a semiconductor light emitting element that uses group-III nitride semiconductors and includes a light emitting layer having a multiquantum well structure suffers from reduction in the light emission efficiency in some cases when many holes or electrons are not recombined with each other in the multiple well layers of the light emitting layer. The light emission efficiency is considerably reduced especially under the conditions of a high current density.
An object of the present invention is to increase the light emission efficiency of a semiconductor light emitting element and maintain the increased efficiency also in a high current range while keeping the unity of wavelength of light outputted from the semiconductor light emitting element.